SYNOPSIS
perf kvm [--host] [--guest] [--guestmount=<path>
[--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
{top|record|report|diff|buildid-list} [<options>]
perf kvm [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
| --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>]
'perf kvm stat [record|report|live] [<options>]
DESCRIPTION
There are a couple of variants of perf kvm:
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'perf kvm [options] top <command>' to generates and displays a performance counter profile of guest os in realtime of an arbitrary workload.
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'perf kvm record <command>' to record the performance counter profile of an arbitrary workload and save it into a perf data file. We set the default behavior of perf kvm as --guest, so if neither --host nor --guest is input, the perf data file name is perf.data.guest. If --host is input, the perf data file name is perf.data.kvm. If you want to record data into perf.data.host, please input --host --no-guest. The behaviors are shown as following: Default('') -> perf.data.guest --host -> perf.data.kvm --guest -> perf.data.guest --host --guest -> perf.data.kvm --host --no-guest -> perf.data.host
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'perf kvm report' to display the performance counter profile information recorded via perf kvm record.
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'perf kvm diff' to displays the performance difference amongst two perf.data files captured via perf record.
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'perf kvm buildid-list' to display the buildids found in a perf data file, so that other tools can be used to fetch packages with matching symbol tables for use by perf report. As buildid is read from /sys/kernel/notes in os, then if you want to list the buildid for guest, please make sure your perf data file was captured with --guestmount in perf kvm record.
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'perf kvm stat <command>' to run a command and gather performance counter statistics. Especially, perf 'kvm stat record/report' generates a statistical analysis of KVM events. Currently, vmexit, mmio (x86 only) and ioport (x86 only) events are supported. 'perf kvm stat record <command>' records kvm events and the events between start and end <command>. And this command produces a file which contains tracing results of kvm events.
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'perf kvm stat report' reports statistical data which includes events handled time, samples, and so on.
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'perf kvm stat live' reports statistical data in a live mode (similar to record + report but with statistical data updated live at a given display rate).
OPTIONS
-i, --input=<path>
- Input file name.
-o, --output=<path>
- Output file name.
--host
- Collect host side performance profile.
--guest
- Collect guest side performance profile.
--guestmount=<path>
- Guest os root file system mount directory. Users mounts guest os root directories under <path> by a specific filesystem access method, typically, sshfs. For example, start 2 guest os. The one's pid is 8888 and the other's is 9999. #mkdir /guestmount; cd/guestmount #sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/ #sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/ #perf kvm --host --guest --guestmount=~/guestmount top
--guestkallsyms=<path>
- Guest os /proc/kallsyms file copy. perf kvm' reads it to get guest kernel symbols. Users copy it out from guest os.
--guestmodules=<path>
- Guest os /proc/modules file copy. perf kvm' reads it to get guest kernel module information. Users copy it out from guest os.
--guestvmlinux=<path>
- Guest os kernel vmlinux.
-v, --verbose
- Be more verbose (show counter open errors, etc).
STAT REPORT OPTIONS
--vcpu=<value>
- analyze events which occures on this vcpu. (default: all vcpus)
--event=<value>
- event to be analyzed. Possible values: vmexit, mmio (x86 only), ioport (x86 only). (default: vmexit)
-k, --key=<value>
- Sorting key. Possible values: sample (default, sort by samples number), time (sort by average time).
-p, --pid=
- Analyze events only for given process ID(s) (comma separated list).
STAT LIVE OPTIONS
-d, --display
- Time in seconds between display updates
-m, --mmap-pages=
- Number of mmap data pages (must be a power of two) or size specification with appended unit character - B/K/M/G. The size is rounded up to have nearest pages power of two value.
-a, --all-cpus
- System-wide collection from all CPUs.
-p, --pid=
- Analyze events only for given process ID(s) (comma separated list).
--vcpu=<value>
- analyze events which occures on this vcpu. (default: all vcpus)
--event=<value>
- event to be analyzed. Possible values: vmexit, mmio (x86 only), ioport (x86 only). (default: vmexit)
-k, --key=<value>
- Sorting key. Possible values: sample (default, sort by samples number), time (sort by average time).
--duration=<value>
- Show events other than HLT (x86 only) or Wait state (s390 only) that take longer than duration usecs.